1. Field of the Invention
The invention pertains to a method for detecting hot targets on the Earth, to at least one satellite suitable for this purpose, and to at least one receiving unit for this purpose.
2. Description of the Related Art
High-temperature events on the surface of the Earth often cause environmental catastrophes. Such high-temperature events include forest and savannah fires, fires of surface coal mines, volcanic activity, and others (e.g., oil well fires, pipeline fires, etc.). A quite essential precondition for the determination of the parameters of an event such as its temperature, area covered, and location is the reliable remote detection of the high-temperature event as a “hot target object” on board aircraft or space vehicles. Remote detection of hot target objects on board aircraft is possible primarily on the local or regional scale. Detection systems for high-temperature event catastrophes on board space vehicles can work on a global and regional scale. New data evaluation methods are required on board, for which the existing sensors on space vehicles and aircraft, such as those know from U.S. Pat. No. 5,602,543 A, are not sufficient.
There are various approaches to the problem of detecting hot targets (hot spots) on the surface of the Earth.
DE 198 40 873 A1, for example, describes a method and a device for the automatic detection of forest fires. The disadvantage of such stationary, earth-bound systems is that they observe the fire horizontally; that is, only the smoke column of a fire is detected. These systems are designed primarily for the early detection of fires, not for the acquisition of data concerning intensity, effective area, and effective temperature.
For daytime fire detection, EP 0 892 286 A1 describes a method for the adaptive, combined threshold processing of hot targets on the Earth's surface. By means of the method described here, it is possible to detect hot targets with a high degree of reliability. The IR (i.e., infrared) data, preferably acquired from one or more satellites, are transmitted to a ground station and evaluated there according to the method. The data, which are then also processed graphically, are made available to interested third parties over the Internet, for example. The disadvantage of the known satellite-supported systems is that they are relatively expensive because of the personnel-related and technical resources required at the ground station. There is also a not inconsiderable delay between the time at which IR data are acquired and the time at which the processed data become available to third parties.
The technical article by Zhukov et al. entitled “BIRD Detection and Analysis of High-temperature Events: First Results”, Proc. SPIE, 2003, Vol. 4886, pp. 160-171, describes another multi-channel threshold method for detecting hot targets, to the disclosure of which reference is herewith explicitly made.